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United States Patent | 6,104,254 |
Iravani | August 15, 2000 |
The present invention comprises a CMOS voltage controlled oscillator (VCO) circuit for operation at frequencies of 1 GHz and above. The circuit of the present invention includes a voltage-to-current converter circuit for receiving a VCO input, a replica circuit coupled to the voltage-to-current converter circuit, and a first and second VCO cell coupled to the replica circuit. The first and second VCO cells are also coupled to one another. The circuit of the present invention also includes a VCO output for transmitting a VCO output signal. A first current source is coupled to the first VCO cell to transmit a first current from a power supply to the first VCO cell. A second current source is coupled to the second VCO cell to transmit a second current from the power supply to the second VCO cell. The first VCO cell and the second VCO cell both include respective first and second load transistors coupled to the replica circuit such that the CMOS voltage controlled oscillator circuit of the present invention reliably generates a VCO output signal having a frequency of 1 GHz or above.
Inventors: | Iravani; Kamran (San Jose, CA) |
Assignee: | VLSI Technology, Inc. (San Jose, CA) |
Appl. No.: | 972792 |
Filed: | November 18, 1997 |
Current U.S. Class: | 331/57; 327/261; 331/175; 331/177R; 331/185 |
Intern'l Class: | H03L 007/099; H03B 005/02 |
Field of Search: | 331/57,175,177 R,185 327/157,261,280 |
5412349 | May., 1995 | Young et al. | 331/34. |
5563553 | Oct., 1996 | Jackson | 331/57. |
5767748 | Jun., 1998 | Nakao | 331/57. |
5963101 | Oct., 1999 | Iravani | 331/57. |